1. Field of the Invention
The present invention relates to an acoustic device such as an audio device, which includes a plurality of sound sources of a CD, an MD, a radio and so on, and a speaker and a headphone for outputting sound based on sound signals from the individual sound sources and which is provided with a function such as a dual media function to output the sound based on the sound signals from the different sound sources simultaneously from both the speaker and the headphone.
2. Description of the Related Art
In recent years, the audio device having such dual media function is applied to a vehicular audio system.
FIG. 5 is a system construction diagram showing the entire construction of the vehicular audio system having a general dual media function.
The vehicular audio system 100, as shown in FIG. 5, includes: a body device 101 arranged on the front side in a vehicular compartment and having a plurality of functions of sound sources such as CD or radio; a front operation unit 102 for operating the body device 101 on the front side; a rear operation unit 103 for operating the body device 101 remotely on the rear side in the compartment; and a speaker 104 and a headphone 105 for outputting sound based on sound signals coming from the sound source functions of the body device 101.
The speaker 104 is composed of two front speakers 104A arranged on the front side, and two rear speakers 104B arranged on the rear side. On the other hand, the headphone 105 is arranged on the rear side.
Here, the front operation unit 102 corresponds to the front panel as arranged on the front side of the body device 101, and the rear operation unit 103 corresponds to the remote operation unit arranged on the rear side.
The body device 101 has a dual media function and can be switched and set to a single mode or a dual mode in response to a predetermined operation from the front operation unit 102.
In the single mode, the sound based on the sound signals from one of the sound sources are output exclusively from the speaker 104.
In the dual mode, the sound based on the sound signals from one of the sound sources are output from the speaker 104, whereas the sound based on the sound signals from another sound source are output from the headphone 105.
In case the body device 101 is demanded for provisions of different sound sources such that a passenger on the front side requests the radio whereas a passenger on the rear side requests the CD, the dual mode can be set by operating the front operation unit 102 in a predetermined manner. Then, the sound based on the sound signals from the radio requested by the front passenger can be output from the speaker 104, and the sound based on the sound signals from the CD requested by the rear passenger can be output from the headphone 105.
In short, the front passenger and the rear passenger can accept the sound signals from the different sound sources through the speaker 104 and the headphone 105.
According to the vehicular audio system 100 having such dual media function, the dual mode can be set in response to the predetermined operation of the front operation unit 102. In the duel mode thus set, the different sound sources can be provided through the speaker 104 and the headphone 105. Therefore, the front and rear passengers can accept the individual provisions of the sound signals from the different sound sources through the speaker 104 and the headphone 105.
According to the vehicular audio system 100 having the aforementioned dual media function, however, in case the rear passenger requests the provision of the sound source different from that of the front passenger while the power source of the body device 101 is OFF, the rear passenger can turn ON the power source of the body device 101 with the rear operation unit 103 but not in the dual mode. Therefore, the rear passenger has to ask the front passenger to set the dual mode through the front operation unit 102 so that the front passenger is burdened with the setting operations.